Can 4v/115 run smothly on 3 cyl at WOT?

[ArtSmart]

Here is a problem I've got 2001 V4(60 deg. loop)115 Johnson(If I remember it correctly - 115VXSIF)It surges at rpms higher than 3000. It feels like one cylinder drops in and out intermittently. I know for sure that it is not fuel supply (checked lines, ran from separate tank, replaced VRO2 and rebuild carbs). Now to test whether it is one of the coils or not I figured I will disconnect one spark wire at a time and ran it WOT. The idea is that if it is one cylinder that drops the spark intermittently, I will see drop of power but it would run smoothly, however if I remove a wire from a good cylinder, then the engine will still surge or possible stall.

 

[Boilermaker]

Re: Can 4v/115 run smothly on 3 cyl at WOT?

Not to say it IS a fuel problem, but if a carb has a clogged jet or bad needle valve/float, ect.>>>you wouldn't change anything by swapping fuel sources. All switching tanks tells you is that its not the tank or fuelline for that tank.<br />Good Luck

 

[ArtSmart]

Re: Can 4v/115 run smothly on 3 cyl at WOT?

Thank you for your suggestion, Boilermaker. However, I did rebuild all 4 carbs and can guarantee it is not it (I mentioned it in the previous post). On top of that I tested my fuel pressure on the low pressure side and the high pressure side, and all checks out OK (No vacuum on the low side and pressure about 6 PSI on the high side dropping to 3.5 psi when a float valve in the carburator opens)